Frost Dates for 95965 — Oroville, California

Half of springs at Oroville, CA see their last 32°F night by January 30; only one in ten is past it by December 26, and one in ten still has one after March 3. Planting tender crops after February 12 leaves a 30% risk of a frost on them, after February 22 20%, and after March 3 10%. The 32 days between the even-odds date and the one-in-ten date is wider than at 55% of the 220 California stations behind this site's ZIP pages, so a fixed calendar date is a gamble here.

In fall the first 32°F night comes by December 13 in half of years, as early as November 21 one year in ten, and holds off past January 11 one year in ten. A hard freeze of 28°F follows 12 days later, around December 25; in spring the one-in-ten date for 28°F is February 4, 27 days before the 32°F one. The freeze-free season lasts 321 days in a typical year, longer than at 75% of the 219 California stations; it reaches 357 days one year in ten and falls short of 276 one year in ten. On average 16 nights a year drop to 32°F or below. Nights of 36°F, when frost can still settle on leaves in low, open spots, continue 37 days longer, to about March 8, and return around November 27. A 24°F night is unusual: 18% of winters had one.

July is the warmest month at Oroville, CA, averaging 97°F by day and 63°F at night; January is the coldest at 58°F and 40°F. From March to October the chance of a 32°F night stays under 10% each month. In spring, February still brings one in 37% of years.

Warmth for growing adds up to 5,179 growing degree days a year (base 50°F), more than at 70% of the 283 California stations. 38% of them (1,990) have built up by the end of June, and July adds the most, 927. Precipitation totals 30.5 inches a year, most in January (5.8") and least in July (0.0"); May to September bring 8% of it.

The nearest other station, Oroville Municipal Airport, CA, 5 miles south of Oroville, has a last frost 1 day earlier (January 29), a first frost 6 days earlier (December 7), a season 4 days shorter.

Measurable snow is rare here: only 0 of 27 winters from 1991 to 2020 recorded 0.1 inch or more at Oroville, CA, 3.4 miles away, so there is no typical first-snow date to plan around.

ZIP 95965 is 3 miles from Oroville, CA, which stands at 171 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 1 other ZIP code shares the station; its figures are presented in full for 95966 (Oroville). The 2023 USDA Plant Hardiness Zone Map lists ZIP 95965 in zone 9b, the band where the coldest night of the year averaged 25 to 30°F (-3.9 to -1.1°C) over 1991–2020; a zone describes winter lows, not frost dates.